<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title>date</title>
	</head>
	<body>
		<div id="div1"></div>
		<script>
			var date1 = new Date();
			for(let i=1;i<=10000;i++){
				console.log(i);
			}
			var date2 = new Date();
			div1.innerHTML = date2-date1;
		</script>
	</body>
</html>